The FDA has warned against the use of teething products containing a substance that can “pose a serious risk” to infants and children.

Over-the-counter products containing the anesthetic substance benzocaine are marketed to ease the pain of gums made sore by teething. Oral products for adults to treat sore throats, canker sores and irritation of the mouth and gums can also contain benzocaine.

The FDA highlighted in a statement that products such as Anbesol, Baby Orajel, Cepacol, Chloraseptic, Hurricaine, Orabase, Orajel and Topex, as well as store-brand alternatives, have benzocaine as an active ingredient.

Benzocaine can trigger methemoglobinemia, a condition caused by elevated levels of a form of hemoglobin called methemoglobin. Methemoglobinemia can be deadly as it causes the amount of oxygen carried in the blood to drop.

Dr. Janet Woodcock, director of the FDA’s Center for Drug Evaluation and Research, said in a statement: “Given the accumulating evidence regarding benzocaine’s association with methemoglobinemia, we are taking necessary action to work with industry to discontinue the distribution and sale of over-the-counter benzocaine oral health products intended for teething pain, and add warning information about methemoglobinemia and a contraindication against use for teething pain and against use in children under two years of age to the remaining oral health care drug products containing benzocaine.”

The FDA has ordered companies to stop selling teething products containing benzocaine, and said it will take action against those who refuse to comply. Other products containing benzocaine must carry a warning against the potential risks, the statement said.

FDA Commissioner Dr. Scott Gottlieb said in a statement: “Because of the lack of efficacy for teething and the serious safety concerns we’ve seen with over-the-counter benzocaine oral health products, the FDA is taking steps to stop use of these products in young children and raise awareness of the risks associated with other uses of benzocaine oral health products.

“In addition to our letters to companies who make these products, we urge parents, caregivers and retailers who sell them to heed our warnings and not use over-the-counter products containing benzocaine for teething pain.”

Those concerned by the warning are advised to check if benzocaine is an active ingredient in products, and keep an eye out for symptoms of methemoglobinemia if they are used.

Signs and symptoms include short breath and pale, gray, or blue-colored skin, lips and nails, as well as fatigue, dizziness, headache and a fast heart rate. These can develop in minutes or up to two hours after using the drug. Anyone with these symptoms should seek medical attention immediately, according to the FDA.